Sterilizer



Feb. 14, 1950 E. R. SCHIPANSKI 2,497,326

STERILIZER Filed April 26, 1947 3 Sheets-Sheet l a I? .217 2. Zhwentor 514/; 5CH/9A4V5/fb Feb. 14, 1950 E. R. SCHIPANSKI 2,497,326

STERILIZER Filed April 26, 1947 s Sheets-Sheet 2 & 's

' I Ottomeg Feb. 14, 1950 E. R. scHlPANsKl 2,497,326

STERILIZER Filed April 26, 1947 3 Sheets-Sheet 3 3 nnentor 1514/1 5c/// /4A/5/r/,

3 Gttomeg i atented UT-Nl TED S TATES PATENT F F :1 CE

ST-E RILIZER 'EnfilRfSc'liipanski, Gardena, Calif.

-Application April 26, 1943?, Serial No. 344,100

11 Claims.

.My invention relates generally 'to medical and dental sterilizing equipment, and more particularly 't'o instruments of the class describedknown as non-pressure sterilizers. Such devices are widely used by doctors and dentists fforster'ilizing surgical instruments, surgical needles, .sutures, dental burrs, and the like. Basically, the non-pressure sterilizer "is comprised .of a boiler incorporating a h'e'a'ter and-a itray-adapt'edto be suspended Within the "boiler to support the articlesto'be sterilized therein. It'is'the escarpmetice to, providev a housing to enclose the boiler tray and a lid to cover the housing. Furthermore, it is usual practice to s'uspend'the tray fromth'e lid so that the tray is withdrawn from the boiler when the'lidis raised. I

Such equipment as designed in the past has had several disadvantages .vvhich have interfered with its ifacile and efficient .use. Among s'uch disadvantages .are the following. "Sterilizers of the class described in coininbn use heretofore have required the disassembly of allargepzar t of the structure 'in order .to replace the boiler should thisbecome necessary. 'Since the boiler is apart most likely to'be replaced in equipment of this type, -the-necessity of returning the equipmen'tt'othe factory, or possibly .discardingit .entirely, when the boiler is worn .outfhas resulted in considerableinconvenience and economic loss.

In -.controlling the operation of the "heater in devices o'f;.the.'cla ss described,.it.is desirable that thelheat delivered Qtherebybelmaintained at lj us't that required to -.continiuously 'boil the water in theiboilerandno more. Furthermore, should the boilerboil dry, it is important that the heater be turned off at once. Such control .hasbeen accomplished in mostcases' by means of athermo stat deriving its heat directly "from theheater. Such construction has the -.d'isadvaritage "that "if the rate oflheattransfer between theheater and the boiler is not aceuratelyimaintained,ithe heater maybe turned off or controlledbe'forethe water reaches the desired temperature since the control :Iement is responsive to the theater itself rather than to the temperature of the 'water in theboiler. -Becauseofthe frequent heatingand cooling of apparatus of the "class described, and because of corrosion, warping of metallic parts, and "differences in "COefilCi'enl/S of thermal expansion, considerable"diihcultyhas beenencountered in maintaining an accurate temperature control of the boiler water.

Still another disadvantage of previous const'ruction' lies in thefact thatiftthefheatidlivered by the "heater to "the boiler is not "evenly distributecl over theheat transfer surface, vigorous boiling will take place at certain isolated spots on the bottom surface or .the boiler. Such iiso- 1ated"hot spots 'resuwin the-jdeposition-of mineral matter or other solid'sjfrom the boiler water, and furthermore, result in i inefficiency since .considerably more hea't "is dlivered by the heater than is actually required tolkeep the entire 'body of Water at boiling temperature.

A still further disadvantage :in ,prior devices lies in thefact that non pressuresterilizers hereto'fore have imou'nted 'lid-izai's'ing .mechanism on the exterior of theih'ousfing. Due to the fact that such mechanism'isiiniir'itimate contact with theboiler and trayfit sohnbecomesiho't .andbecomes an ever present-dangerjtoth'eoperator who may inadvertently touch the. hot-mechanism and receive as'e'vere burn.

Bearing in "mind the above listed difiiculties encountered in previous equipment of the class described, itisia major object .of my invention to provide a non-pressure sterilizer in which the boiler .may be quickly and .easily removed .for cleaning, repair, or replacement.

'It' is another object of my invention'toprovide such a sterilizer in'vv hich means ar'e'in'corporated to evenly distribute the heat delivered by the heater over alarge surface of aboile'r.

It is -sn11 another -'ob'j'ect of my invention to provide ab'oller and thermostat structurein apparatus ofthe :cla ss'described in'w'hic'h the thermo'static "control element is mounted so as to The principallyresponsive to the temperature oftlthe water 'in "the boiler rather "than the temperature of'th'eiheater.

A further objectdtm'y inventionis 'to pio'vide tray lifting mechanismi'in a non-pressuresterilizer, which mechanism is "entirely enclosed to prevent accidental contact "therewith by the operator "or oth'erfpersons.

The foregoing and other objects and "advantages of myi'nventiomwill become apparent "from the "following description of 'a sterilizer embodying the various'ifeatures'of myinvention.

Briefly described'the "sterilizer described herein iseompfised of: a-completely enclosed outer housing "or cabinet with the removable "boiler, "the lid and tray lifting control, the heaters, "and the thermostatic control enclosedtherein. The movable boiler is held in the structureby a number of pivotallysupp'orted dogs which are operable from outside .ofthe housing'bymeans or a'knob accessible at 'the rear thereof. Heat -is evenly distributed to the bottom of tthe "boiler by means of a relatively large, flat, highly heat conduct ing plate against which the boiler is clamped by means of the aforesaid dogs.

As was earlier stated, it is desirable that the thermostatic control element be responsive to the temperature of the water in the boiler rather than to the temperature of the heater. To this end the thermostatic element is mounted out of direct contact with the heater and heat distribution plate, and furthermore, is spring pressed against the bottom of .the boiler-so that in spite of slight corrosion; warping or differing coefiicients of thermal expansion, the control element will be held tightly against the boiler at all times.

For a more detailed description of my invention, reference should now be had to the attached drawings in which:

Figure 1 is a perspective view of a non-pressure sterilizer embodying my invention" and'with the lid closed;

Figure 2 is an elevational section taken on the line 2-2 in Figure 1;

Figure 3 is a front elevational section taken on the line 33 in Figure 1;

Figure 4 is an elevational section on the line 4-4 in Figure 3with the devic in open position;

Figure 4a is an enlarged detail of portions of the mechanism shownin Figure 4;

Figure 5 is a plan section taken on the line 5-5 in Figure 3 with boiler removed; and,

Figure 6 is an elevational section taken on the line 6--6 in Figure 5.

Referring now to the drawings, it will be seen that the numeral l indicates generally a housing enclosing the sterilizer embodying my invention. The housing In is comprised of a cast or otherwise fabricated base frame ll'and a similarly fabricated top frame l2 joined by a sheet metal shell l3, the shell being secured to the frame by means of screws 9 around'the upper and lower edges. 3

The bottom of the housing is closed by a plate l4 secured in a suitable recess in the lower frame section I l and the entire unit is supported on four feet I secured to the lower frame H. A hinged lid providing a closure for the top of the housing is mounted in a recess in the upper frame l2 and is secured thereto by means of a pair of hinges I8 and I9.

Lifting handles l6 are provided at the ends of the housing whereby to conveniently lift or move the device. Variouscontrols and handles projecting from the" housing will be described in detail hereinafter.

The boiler 20 of the present sterilizer is constructed in the form of a rectangular tank of suitable proportions to be received through the upper opening, the frame l2. The boiler is supported therein on its bottomsurface and is removably secured against a supporting plate 46 by a pivotally mounted dog mechanism now to be described. The dog operating mechanism is rotatably carried on a longitudinal rod 23 which is journally secured on a pair of Z-shaped brackets 22, which in turn 'are secured to the lower frame II. A horizontal intermediate-partition member 32 is supported by the brackets 22 at the upper ends thereof and is additionally supported by four flanged struts 22' which connect it to the lower frame H as shown in Figures 3 and 4. I

A tubular sleeve 24 is supported for free rotation on the rod 23 intermediate the ends thereof. Rotation of the sleeve in one direction serves to unlock the boiler securing dogs 38 about to be described, while rotation of the sleeve in the other direction moves the dogs 38 inwardly so as to clamp the boiler 20 in place. The sleeve 24 is driven in such rotation by means of a pinion 25 aflixed to the left end thereof (as viewed in Fig ure 3), the pinion 25 being driven by a slidably mounted rack 26 engaged therewith. The rack 26 is supported in a bracket 2! which depends from the partition 32 and has a suitable seat formed therein at the lower end whereby to receive the rack and permit longitudinal sliding motion thereof while preventing rotation thereof about its longitudinal axis.

In order to drive the pinion 25 by moving the rack back and forth along its longitudinal axis, this member is threaded at its outer end as indicated by the numeral 30 in Figure 2. An interiorly threaded sleeve 29 isengaged with the threads 30 and is journally supported in the shell 13. Longitudinal motion of the sleeve 29 is prevented by a forked bracket 28 secured to the intermediate partition 32 depending therefrom, and engaged with a groove in the sleeve'2t. A knob 3| is secured to the sleeve 29 for manual rotation thereof, and as shown in Figure 2, is positioned in the rear of the sterilizer. Thus rotation of the knob 3| rotates the sleeve 29, and since the rack 26 is prevented from rotation by the dependin bracket 2'1, such rotation of the sleeve 29 causes inward or outward motion of the rack along its longitudinal axis, the direction of such motion dependent on the direction of rotation of the sleeve.

In order now to move the dogs 38 in response to rotation of the sleeve 24, these parts are interconnected by a toggle mechanism comprised of a pair of links 35 and a double crank 34 secured to the sleeve 24. All connections between the dogs 38, the links 35, and the crank 34 are pivotal in nature so that rotation of the crank 34 pulls inwardly on the links 35, and thus pulls inwardly on the lower ends of the dogs 38. The dogs 38 being pivotally supported intermediate their ends by the intermediate partition 32, the upper ends of the dogs are moved outwardly by inward motion of the lower ends thereof. Conversely, rotation of the crank 34 to the horizontal position shown in Figure 2, pushes the links 35 outwardly and forces the upper ends of the dogs 38 inwardly. A pair of lugs 40 are secured to he sides of the boiler 20 positioned to be engaged by the upper ends of the dogs 38, and as will be noted from an examination of Figure 2, the lugs 40 are formed with a slanting upper surface so that pressure engagement of the dogs 38 forces the boiler downwardly toward the intermediate partition 32, pressing the boiler into secure engagement with the plate 46.

Turning now to a description of the heater and heat distribution means, reference should be had to Figures 2, 3, and 5. As was stated earlier, it is desired to deliver and distribute the heat evenly over a wide surface of the bottom of the boiler 20. The heat is produced by a pair of ring-shaped electric heating elements 45 of conventional de sign, and is distributed by means of the horizontal plate 46 which is, as above stated, placed in intimate contact with the bottom of the boiler 20. The heat distribution plate 46 is supported on the upper surface of the partition 32 and secured thereto by means of eight screws 41. As is shown in Figure 6, a pair of downward projections 48 are formed in the heat distribution plate 46 adjacent each of the screws 4'! whereby to support the plate at a slight distance above the partition 32 for the purpose of preventing Kiwi.

excessive transfer of heat :from the distribution plate '46 to the partition 82 and thence to the outer housing.

Each of the heating elements 45 is secured in a suitable circular recess to the upper surface of the intermediate partition 32 being located therein by means of downwardly projecting studs or locating pins 49 formed in the heating element and engaging complementary apertures formed in the partition 32.

As will be noted from an examination of Figure 3, the heating elements have boxes 49' formed therein adjacent each of the locating pins 49. Thus the heating element 45 is supported away from the partition 32 whereby to reduce the rate of heat transfer from the heating element 45 to the partition 32. The heat distribution plate 46 is held in close heat transfer relationship with the heating element 45 by means of a pair of clamping screws 50 which are located at the center of each element, pass through the plate 46, the partition 32, and are secured by a nut 5| at the under surface of the partition 32.

4 Thus the greatest part of the heat delivered by the heating element 45 passes directly into the heat distribution plate 46 and thence into the boiler 20 heating the water therein. An optimum heat transfer from the plate 46 is maintained at all times due to the downward pressure urged by the clamping dogs 38.

As was previously stated, it is desirable that the heat control unit in a device of the class described be principally responsive to the temperature of the boiler rather than to the temperature of the heating element. The temperature sensitive element in the present instance is a liquid filled bulb 60 of conventional design which is connected by a capillary tube 6| to a controlling thermostatic switch 62 having a control knob 63 projecting from the front of the housing. The details of the thermostaticswitch 62 being of conventional design, need not be described.

In order that the temperature responsive bulb 60 be held in close heat transfer relationship with the boiler and its contents at all times, this bulb 611 is pressed or otherwise securely fastenedi-nto a heat conducting plate 65, which in turn is held against the lower surface of the broiler -20 by means of four compression springs 66. The compression springs are anchored against threaded studs 81, which in turn are secured in the intermediate partition 32. :As will be noted in Figure 5, a space '68 is left between the plate 65 and the heat distribution plate 46, a rectangular opening being formed in the latter member in order to clear the plate 65. By reason of the spring mounting of the plate 65, it is always urged upwardly against the under surface of the boiler 20, and should portions of the boiler or .portions of the heat distribution plate 48 warpso as to change their relative position somewhat, the plate 65 will move under the urgingof the springs 66 and always be held in close heat transfer relationwith the boiler and its contents.

Turning to a discussion of the mechanism by which the lid ll is raised to give access to the interior of the sterilizer, reference shouldnow be had to Figure 3. In Figures 3 and 4 it will 'be noted that the hinges l8 and '19 are formed with downwardly projecting yoke portions 18' which extend into the housing. Pivotally secured in each of the yokes i8 is 'a'downw'ardly extending thrust link 18, one such link being provided at each eridci the-housing. Each of the links is secured by a knuckle .joint'to a crank arm 1l-,the

"crank arm n bein keyed to the end or the four nall'y supported shaft 23 as best seen in Figure 3. As can be seen best in Figure 4, the crank arm 11 is formed with a projecting lug 11" adjacent the knuckle joint, and furthermore, the link 10 extends somewhat beyond the pivot "I2 of the joint so as to strike the lug 'l'l whereby to prevent the relative pivotal motion of the members 14 and I'll beyond a substantially straight position indicated in full lines in Figure 4. Thus when the lid is in an upright position such as shown by the full lines in Figure 4, the members l0 and H form a relatively straight strut between the yoke I 8" on the axis or the rod 23 whereby to hold the lid ii in an upright position.

In order now to raise and lower the lid from the i ront of the housing, one of the crank arms H at the right-hand end of the housing as viewed in Figure 1, is formed in hell crank fashion with a lever 13 extending forwardly through a slot H in the forward surface of the shell I3. The lever 13 'isprovid'ed with a heat insulating 15. As can be best seen in Figure 4, downward pressure on the handle '15 rotates the two crank arms H in an anti-clockwise direction, thus thrusting upwardly on the links H! and raising the lid to the position shown in full lines in Figure 4. The lid l1 remains in this position, being held there by the locking action between the members T0 and H which takes place at the pivotal joint between the two members due to the lower end of the links 'lll striking against the lugs To again lower the lid, the handle is raised "to the position shown in phantom lines in Figures '4.

As is shown in Figure 4a, the connection of the members 10 and 11 is efiected by the engagement of the pivot pin 12 with an elongated slot 10 in the lower end of the links -10. Thus when it is desired to remove the boiler as previously described, the lid may be pushed rearwardly to the position shown in phantom lines in Figure *4 so as to'clear the boiler when it is removed through the aperture in the upper frame I2.

Articles to be sterilized in the boiler 20 are held in a tray which is suspended within the boiler 20 as shown in Figures 2 and 3. The tray80 is provided with four button-like feet 80' which are positioned and adapted to rest on the bottom -"of the boiler 20 and support the tray'above the bottom of the boiler. Thebottom of the tray isI-pro v-idcd with perforations Bi and a pair of handles 82 are secured to the ends of the tray by which it may be lifted out of the boiler in a manner about to be described.

As was previously mentioned, it is desirable that the tray be lifted from its position within boiler simultaneously with the lifting of the lid H. To this end, the tray 80 is suspended from the lid I! by a pair of depending brackets 84, the brackets '84 being connected to the hinges l8 and 1 9 by a pair of suspensionlinks which are received i-n yoke portions I 9 formed in the hinges i8 and 1-9. The brackets =84 are provided'with upwardly projecting pins 84 which engage certain of the perforations 81 in order to Drover-it the-tray from s1i'din'g forwardly or rearwardly the brackets 84. As can be seen in Figures 2 and 4, the upper ends of the suspension links 85 are formed with hook-like apertures 86 whereby they'are adapted to hook over a pin 8'6"'secured in the yoke portion I 9. The purpose'o'f the hooksh'aped aperture 86 is that the tray-supporting brackets '84 may be disconnected from the lid in order that the boiler'm'ay be removed.

. The lid U0 .is maintained in a horizontal 1903b tion at all. times during the lifting thereof by means of a pair of horizontal arms 81, each pivotally connected to the boiler at one end by a shoulder screw 88 and to the tray-supporting bracket 84 at the other end by a rivet or other suitable pivotal connection. Thus the arms 81 serve as a parallel mechanism to maintain the brackets 84, and hence the tray 80, in a horizontal position atall times. Thus it will be seen that when the lid is lifted to the position shown in full lines in Figure 4, the tray is drawn upwardly by the link 85 to the position shown in full lines in Figure 4. When in this position the tray may be lifted from the brackets 84 in order to carry the sterilized articles to their intended place of use, .and another loaded tray may be placed on the brackets in order that it may be lowered into the boiler for the purpose of sterilizing articles therein. If it is desired to remove the boiler, the brackets 34 must be disconnected from the lid as previously stated, this being accomplished by unhooking the links 85 from the pin 86 as previously described.

A suitable electrical connector 90 is provided at the rear of the housing for the purpose of coni.

necting the sterilizer to a source of electric power for the heaters 45. The wiring within the housing comprises leads 9| from the connector 90 to the thermostatic controls 62, and leads 92 from the thermostatic control to the electric heaters 45. The details of the circuit wiring being conventional, are not described herein.

1 Thus it will be seen that I have provided a nonpressure sterilizer of the class described which incorporates the following features.

First, the heated portions of the mechanism are protectively enclosed by the housing In so as to prevent accidental contact therewit Second, heat from the electric heaters 45 is distributed uniformly over the bottom of the boiler 20 by means of the heat distribution plate 46, and the plate 46 is so mounted to the partition 32 that excessive heat transfer from the plate 46 to the partition 32 is prevented.

"Third, the pivotable dogs 38 and the mechanism connected thereto permit easy and rapid removal of the boiler 20 should this be necessary. Fourth, the thermostatic control element is, by reason of the heat transfer plate 65, responsive principally to the temperature of the boiler rather than'to the temperature of the heating elements 45, this condition of optimum heat transfer being maintained at all times through the operation of the compression springs 66. Fifth, the general organization and structure of the sterilizer embodying my invention provides for maximum co n venience in operation and for a degree of portability not attained in previous devices of the class described.

While the apparatus shown and described herein is fully'capable of achieving the objects and providing the advantages hereinbefore stated, it is capable of considerable modification Within the spirit of the invention and for this reason I do not mean to be limited to the form shown and described herein, but rather to the scope of the appended claims.

- I claim:

1. sterilizing apparatus of the class described including means forming a housing having an opening with a hinged lid; mechanism within said housing operatively connected to said lid, said mechanism having a handle portion extending outside of said housing operable to open said closure; a boiler within said housing adapted to pass through said opening; movable mans'withiii said housing to releasably secure said boiler therein; releasing means operatively associatedwith said securing means and extending outside of said housing whereby to permit selective manual operation of said securing means to secure or release said boiler; means in said housing to support said boiler on a relatively large bottom area thereof said support means being held in close heat exchange relation with said boiler by said movable securing means; heater means mounted in close heat exchange relation to said support means whereby to evenly heat said boiler through said support means; thermostatic control means for said heater including a temperature responsive element in heat exchange contact with said boiler and spring mounting means to urge said element against said-boiler; a tray in said boiler adapted to hold articles for sterilization by liquid in said boiler; and support mechanism for said tray connected to said lid whereby to move said tray out of said boiler and housing in response to opening of said lid.

2. sterilizing apparatus of the class described including: an enclosed housing having a top opening; a closure for said opening hingedly secured to said housing; a rod longitudinally disposed andjournally supported in said housing; a pair of crank arms secured to said rod, one adjacent each end thereof; a pair of links each pivotally connected at one end thereof to said closure and at the other end thereof to an outer end of one of said cranks whereby rotation of said rod opens said closure; a lever fixed to' one end of said rod and projecting out of said hous ing whereby to rotate said rod by pressure on said lever to open said closure; a boiler of generally rectangular shape positioned in said housing, adapted to pass through said openin and having a plurality of lugs attached to the sides thereof; a horizontal support plate in said housing adapted to support said boiler with a relatively large surface area of said boiler in heat exchange contact with said plate, said plate having a portion cut away to expose a portion of the bottom surface of said boiler; a plurality of dogs pivotally mounted in said housing and adapted to be moved to engage said lugs whereby to clamp said boiler against said plate; a member rotatably mounted in said housing and having a plurality of cranks fixed thereto; links connecting said cranks on said rotatable member'to said dogs whereby rotation of said member in one direction moves said dogs into engagement with said lugs to clamp said boiler, and rotation of said member in the other direction moves said dogs out of said engagement to release said boiler; heater means secured to said plate; and thermostatic control means for said heater including a temperature sensitive element resiliently secured against said exposed portion of said boiler surface and out of direct heat exchange contact with said plate.

3. sterilizing apparatus of the class described including: housing means having an opening with a hinged closure, manually operable mechanism for opening and closing said closure, and boiler supporting and heating means formed therein; a removable boiler in said housing, supported on said support means, and adapted to receive articles for sterilization therein; securing means including a plurality of movable dogs mounted in said housing and adapted to engage said boiler to secure the same against said supporting means; and mechanism operable from outside said housing and connected to said securing means whereby to selectively operate the same to secure or release said boiler.

4. sterilizing apparatus of the class described including: a housing having an opening with a hinged closure; mechanism in said housing to open and close said closure; an article-receiving tray dependently carried by said closure; a removable boiler adapted and positioned in said housing to receive said tray when said closure is in a closed position; movable members in said housing adapted to engage and secure said boiler therein; mechanism operatively connected to said members and projecting outside of said housing whereby to manually operate said movable members to selectively engage or disengage said boiler; and means in said housing to maintain said boiler at a temperature suflicient to boil water therein.

5. Sterilizing apparatus of the class described including: means forming an enclosed housing; a removable boiler in said housing; a supporting plate fixed in said housing and adapted to engage a relatively large surface of said boiler in heat exchange contact therewith; spacing means in said plate to hold the same out of heat exchange contact with said housing; thermostatic control means for said heater including a temperature sensitive element positioned in said housing adjacent said boiler and out of heat exchange contact with said plate; and resilient means connected between said temperature sensitive element and said housing adapted to urge said temperature sensitive element into heat exchange contact with said boiler.

6. Sterilizing apparatus of the class described including: means forming an enclosed housing having an opening with a hinged closure; a removable boiler in said housing; means in said housing to secure and suport said boiler therein; means in said support means to heat said boiler; thermostatic control means for said heating means including a temperature sensitive element in heat exchange contact with said boiler; and resilient mounting members for said element adapted to urge the same into said heat exchange contact with said boiler.

7. sterilizing apparatus of the class described including: a housing having an opening with a hinged closure therefor; mechanism in said housing to open and close said closure; a boiler positioned in said housing and adapted to be removed through said opening; means dependently and detachably secured to said closure to support an article-receiving tray in said boiler when said closure is in a closed position and to support said tray out of said boiler when said closure is in an open position; a plurality of parallel arms pivotally connected between said boiler and tray supporting means whereby to hold said tray horizontal during motion into and out of said boiler; and means in said housing to heat said boiler.

8. sterilizing apparatus of the class described including: means forming an enclosed housing with an opening therein; a closure for said opening hingedly attached to said housing and having a plurality of attachment members projecting from the inner surface thereof; a removable boiler in said housing adapted to be heated to boil water therein; tray supporting means pivotally attached to said boiler whereby to support a tray in horizontal position for movement into or out of said boiler; and connecting links pivotally attached to said tray supporting means and detachably connected to said attachment members whereby opening of said closure moves said tray out of said boiler and whereby said tray supporting means may be disconnected from said closure to permit removal of said boiler from said housing.

9. sterilizing apparatus of the class described including: means forming an enclosed housing having a top opening with a normally horizontal hinged closure; a removable boiler in said housing; means to heat said boiler; a rod journally mounted in longitudinal position with said housing; crank arms secured to the ends of said rod; connecting rods connected between said crank arms and said closure whereby rotation of said rod operates through said crank arms and connecting rod to lift said closure to a substantially vertical position; a bell crank arm fixed to said rod and projecting through said housing whereby to manually rotate said rod to lift said closure; and pin and slot connection means in said crank arms and connecting rods whereby to permit said closure to be moved beyond said substantially vertical position whereby to permit removal of said boiler through said opening.

10. In sterilizing apparatus of the class described having an outer housing with an opening and a hinged closure; means to support a removable boiler within said housing; movable clamping means adjacent said supporting means operable to engage and secure a boiler within said housing against said supporting means; and thermostatically controlled heating means secured to said supporting means and adapted to heat said boiler through said supporting means.

11. In sterilizing apparatus of the class described: means forming an enclosed housing having a stationary portion with a top opening and a hinged closure for said opening; mechanism to open and close said closure, said mechanism including a plurality of pivotally joined members and being connected between said stationary housing portion and closure, said members being substantially entirely within said housing; and a handle of heat insulating material connected to one of said members and projecting through a wall of said housing below the top thereof whereby to operate said mechanism to open and close said closure.

EMIL R. SCHIPANSKI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,384,403 Pelton et a1. July 12, 1921 1,767,034 Anderson June 24, 1930 1,939,713 Meitzler Dec. 19, 1933 

